Cardiovascular disease is now and is predicted to remain the leading cause of death in older women. There is some evidence that estrogen used by postmenopausal women decreases the risk of cardiovascular disease. Insulin resistance is a known risk factor for cardiovascular disease. The use of postmenopausal estrogen replacement therapy (ERT) has been reported to increase insulin sensitivity. Many women do not receive postmenopausal ERT either due to contradictions, poor compliance, or a personal decision against postmenopausal ERT. Alternatives to estrogen are now available for the treatment of osteoporosis. One of these alternatives is raloxifene. Raloxifene is an antiestrogen benzothiophene derivative classified as a selective estrogen receptor modulator (SERM). This classification is based on studies that demonstrate agonist effect on bone, cholesterol metabolism, and antagonist effects on uterine and breast tissue. Based on molecular differences between raloxifene and estrogen, they may not have similar effects on insulin sensitivity. We hypothesize that both raloxifene and estrogen will improve insulin sensitivity in postmenopausal women and that the magnitude of the effect will be similar for both drugs. Fifty subjects will be randomized in a double-bind manner to receive placebo, estrogen, or raloxifene. Moderately obese, postmenopausal women age 60-89 years will be recruited to participate in this study. A screening oral glucose tolerance test will be used to exclude subjects who meet criteria for diabetes. Subjects will have an FSIVGTT and dual energy photon absorptiometry (DEXA) for body composition at the beginning of the study and after 8 weeks of drug therapy. The major outcome variable will be SI. The SI following 8 weeks of raloxifene or estrogen will be compared to the placebo group adjusted for baseline SI and many changes in adiposity and body composition.